llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lld-elf Author: None (llvmbot) <details> <summary>Changes</summary> Backport 673476d96bed306be6ed81a8174f481a9a4b2934 Requested by: @<!-- -->bd1976bris --- Full diff: https://github.com/llvm/llvm-project/pull/151674.diff 5 Files Affected: - (modified) cross-project-tests/CMakeLists.txt (+3-2) - (added) cross-project-tests/dtlto/ld-archive-thin.test (+97) - (modified) cross-project-tests/lit.cfg.py (+2) - (modified) lld/ELF/InputFiles.cpp (+49-10) - (added) lld/test/ELF/dtlto/archive-thin.test (+65) ``````````diff diff --git a/cross-project-tests/CMakeLists.txt b/cross-project-tests/CMakeLists.txt index b4b1f47626073..192db87043177 100644 --- a/cross-project-tests/CMakeLists.txt +++ b/cross-project-tests/CMakeLists.txt @@ -19,11 +19,12 @@ set(CROSS_PROJECT_TEST_DEPS FileCheck check-gdb-llvm-support count - llvm-dwarfdump + llvm-ar llvm-config + llvm-dwarfdump llvm-objdump - split-file not + split-file ) if ("clang" IN_LIST LLVM_ENABLE_PROJECTS) diff --git a/cross-project-tests/dtlto/ld-archive-thin.test b/cross-project-tests/dtlto/ld-archive-thin.test new file mode 100644 index 0000000000000..979da5423962e --- /dev/null +++ b/cross-project-tests/dtlto/ld-archive-thin.test @@ -0,0 +1,97 @@ +REQUIRES: ld.lld,llvm-ar + +## Test that a DTLTO link succeeds and outputs the expected set of files +## correctly when thin archives are present. + +RUN: rm -rf %t && split-file %s %t && cd %t + +## Compile bitcode. -O2 is required for cross-module importing. +RUN: %clang -O2 --target=x86_64-linux-gnu -flto=thin -c \ +RUN: foo.c bar.c dog.c cat.c start.c + +## Generate thin archives. +RUN: llvm-ar rcs foo.a foo.o --thin +## Create this bitcode thin archive in a subdirectory to test the expansion of +## the path to a bitcode file that is referenced using "..", e.g., in this case +## "../bar.o". +RUN: mkdir lib +RUN: llvm-ar rcs lib/bar.a bar.o --thin +## Create this bitcode thin archive with an absolute path entry containing "..". +RUN: llvm-ar rcs dog.a %t/lib/../dog.o --thin +## The bitcode member of cat.a will not be used in the link. +RUN: llvm-ar rcs cat.a cat.o --thin +RUN: llvm-ar rcs start.a start.o --thin + +## Link from a different directory to ensure that thin archive member paths are +## resolved correctly relative to the archive locations. +RUN: mkdir %t/out && cd %t/out + +RUN: %clang --target=x86_64-linux-gnu -flto=thin -fuse-ld=lld %t/foo.a %t/lib/bar.a ../start.a %t/cat.a \ +RUN: -Wl,--whole-archive ../dog.a \ +RUN: -fthinlto-distributor=%python \ +RUN: -Xthinlto-distributor=%llvm_src_root/utils/dtlto/local.py \ +RUN: -Wl,--save-temps -nostdlib -Werror + +## Check that the required output files have been created. +RUN: ls | sort | FileCheck %s + +## No files are expected before. +CHECK-NOT: {{.}} + +## JSON jobs description. +CHECK: {{^}}a.[[PID:[a-zA-Z0-9_]+]].dist-file.json{{$}} + +## Native output object files and individual summary index files. +CHECK: {{^}}bar.3.[[PID]].native.o{{$}} +CHECK: {{^}}bar.3.[[PID]].native.o.thinlto.bc{{$}} +CHECK: {{^}}dog.1.[[PID]].native.o{{$}} +CHECK: {{^}}dog.1.[[PID]].native.o.thinlto.bc{{$}} +CHECK: {{^}}foo.2.[[PID]].native.o{{$}} +CHECK: {{^}}foo.2.[[PID]].native.o.thinlto.bc{{$}} +CHECK: {{^}}start.4.[[PID]].native.o{{$}} +CHECK: {{^}}start.4.[[PID]].native.o.thinlto.bc{{$}} + +## No files are expected after. +CHECK-NOT: {{.}} + + +## It is important that cross-module inlining occurs for this test to show that Clang can +## successfully load the bitcode file dependencies recorded in the summary indices. +## Explicitly check that the expected importing has occurred. + +RUN: llvm-dis start.4.*.native.o.thinlto.bc -o - | \ +RUN: FileCheck %s --check-prefixes=FOO,BAR,START + +RUN: llvm-dis dog.1.*.native.o.thinlto.bc -o - | \ +RUN: FileCheck %s --check-prefixes=FOO,BAR,DOG,START + +RUN: llvm-dis foo.2.*.native.o.thinlto.bc -o - | \ +RUN: FileCheck %s --check-prefixes=FOO,BAR,START + +RUN: llvm-dis bar.3.*.native.o.thinlto.bc -o - | \ +RUN: FileCheck %s --check-prefixes=FOO,BAR,START + +FOO-DAG: foo.o +BAR-DAG: bar.o +DOG-DAG: dog.o +START-DAG: start.o + + +#--- foo.c +extern int bar(int), _start(int); +__attribute__((retain)) int foo(int x) { return x + bar(x) + _start(x); } + +#--- bar.c +extern int foo(int), _start(int); +__attribute__((retain)) int bar(int x) { return x + foo(x) + _start(x); } + +#--- dog.c +extern int foo(int), bar(int), _start(int); +__attribute__((retain)) int dog(int x) { return x + foo(x) + bar(x) + _start(x); } + +#--- cat.c +__attribute__((retain)) void cat(int x) {} + +#--- start.c +extern int foo(int), bar(int); +__attribute__((retain)) int _start(int x) { return x + foo(x) + bar(x); } diff --git a/cross-project-tests/lit.cfg.py b/cross-project-tests/lit.cfg.py index 31c93923ac9ed..ac27753472646 100644 --- a/cross-project-tests/lit.cfg.py +++ b/cross-project-tests/lit.cfg.py @@ -107,6 +107,8 @@ def get_required_attr(config, attr_name): if lldb_path is not None: config.available_features.add("lldb") +if llvm_config.use_llvm_tool("llvm-ar"): + config.available_features.add("llvm-ar") def configure_dexter_substitutions(): """Configure substitutions for host platform and return list of dependencies""" diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp index 71e72e7184b9f..62b54f8217bc3 100644 --- a/lld/ELF/InputFiles.cpp +++ b/lld/ELF/InputFiles.cpp @@ -20,6 +20,7 @@ #include "llvm/ADT/CachedHashString.h" #include "llvm/ADT/STLExtras.h" #include "llvm/LTO/LTO.h" +#include "llvm/Object/Archive.h" #include "llvm/Object/IRObjectFile.h" #include "llvm/Support/ARMAttributeParser.h" #include "llvm/Support/ARMBuildAttributes.h" @@ -1753,6 +1754,39 @@ static uint8_t getOsAbi(const Triple &t) { } } +// For DTLTO, bitcode member names must be valid paths to files on disk. +// For thin archives, resolve `memberPath` relative to the archive's location. +// Returns true if adjusted; false otherwise. Non-thin archives are unsupported. +static bool dtltoAdjustMemberPathIfThinArchive(Ctx &ctx, StringRef archivePath, + std::string &memberPath) { + assert(!archivePath.empty()); + + if (ctx.arg.dtltoDistributor.empty()) + return false; + + // Read the archive header to determine if it's a thin archive. + auto bufferOrErr = + MemoryBuffer::getFileSlice(archivePath, sizeof(ThinArchiveMagic) - 1, 0); + if (std::error_code ec = bufferOrErr.getError()) { + ErrAlways(ctx) << "cannot open " << archivePath << ": " << ec.message(); + return false; + } + + if (!bufferOrErr->get()->getBuffer().starts_with(ThinArchiveMagic)) + return false; + + SmallString<128> resolvedPath; + if (path::is_relative(memberPath)) { + resolvedPath = path::parent_path(archivePath); + path::append(resolvedPath, memberPath); + } else + resolvedPath = memberPath; + + path::remove_dots(resolvedPath, /*remove_dot_dot=*/true); + memberPath = resolvedPath.str(); + return true; +} + BitcodeFile::BitcodeFile(Ctx &ctx, MemoryBufferRef mb, StringRef archiveName, uint64_t offsetInArchive, bool lazy) : InputFile(ctx, BitcodeKind, mb) { @@ -1763,17 +1797,22 @@ BitcodeFile::BitcodeFile(Ctx &ctx, MemoryBufferRef mb, StringRef archiveName, if (ctx.arg.thinLTOIndexOnly) path = replaceThinLTOSuffix(ctx, mb.getBufferIdentifier()); - // ThinLTO assumes that all MemoryBufferRefs given to it have a unique - // name. If two archives define two members with the same name, this - // causes a collision which result in only one of the objects being taken - // into consideration at LTO time (which very likely causes undefined - // symbols later in the link stage). So we append file offset to make - // filename unique. StringSaver &ss = ctx.saver; - StringRef name = archiveName.empty() - ? ss.save(path) - : ss.save(archiveName + "(" + path::filename(path) + - " at " + utostr(offsetInArchive) + ")"); + StringRef name; + if (archiveName.empty() || + dtltoAdjustMemberPathIfThinArchive(ctx, archiveName, path)) { + name = ss.save(path); + } else { + // ThinLTO assumes that all MemoryBufferRefs given to it have a unique + // name. If two archives define two members with the same name, this + // causes a collision which result in only one of the objects being taken + // into consideration at LTO time (which very likely causes undefined + // symbols later in the link stage). So we append file offset to make + // filename unique. + name = ss.save(archiveName + "(" + path::filename(path) + " at " + + utostr(offsetInArchive) + ")"); + } + MemoryBufferRef mbref(mb.getBuffer(), name); obj = CHECK2(lto::InputFile::create(mbref), this); diff --git a/lld/test/ELF/dtlto/archive-thin.test b/lld/test/ELF/dtlto/archive-thin.test new file mode 100644 index 0000000000000..bcd5f138459b0 --- /dev/null +++ b/lld/test/ELF/dtlto/archive-thin.test @@ -0,0 +1,65 @@ +REQUIRES: x86 + +## Test that a DTLTO link assigns Module IDs to thin archive members as expected. + +RUN: rm -rf %t && split-file %s %t && cd %t + +RUN: sed 's/@t1/@t2/g' t1.ll > t2.ll +RUN: sed 's/@t1/@t3/g' t1.ll > t3.ll + +RUN: opt -thinlto-bc t1.ll -o t1.bc +RUN: opt -thinlto-bc t2.ll -o t2.bc +RUN: opt -thinlto-bc t3.ll -o t3.bc + +RUN: llvm-ar rcs t1.a t1.bc --thin +## Create this bitcode thin archive in a subdirectory to test the expansion of +## the path to a bitcode file that is referenced using "..", e.g., in this case +## "../t2.bc". +RUN: mkdir lib +RUN: llvm-ar rcs lib/t2.a t2.bc --thin +## Create this bitcode thin archive with an absolute path entry containing "..". +RUN: llvm-ar rcs t3.a %t/lib/../t3.bc --thin + +## Link from a different directory to ensure that thin archive member paths are +## resolved correctly relative to the archive locations. +RUN: mkdir %t/out && cd %t/out + +## Build a response file to share common linking arguments. +## Note: validate.py does not perform any compilation. Instead, it validates the +## received JSON, pretty-prints the JSON and the supplied arguments, and then +## exits with an error. This allows FileCheck directives to verify the +## distributor inputs. +RUN: echo '%t/t1.a %t/lib/t2.a ../t3.a \ +RUN: --thinlto-distributor="%python" \ +RUN: --thinlto-distributor-arg="%llvm_src_root/utils/dtlto/validate.py"' > rsp + +## Link thin archives using -u/--undefined. +RUN: not ld.lld @rsp -u t1 -u t2 -u t3 2>&1 | FileCheck %s + +## Link thin archives using --whole-archive. +RUN: not ld.lld --whole-archive @rsp 2>&1 | FileCheck %s + +## Check the module IDs in the JSON jobs description. +CHECK: "jobs": [ +CHECK: "inputs": [ +CHECK-NEXT: "{{([a-zA-Z]:)|/}} +CHECK-SAME: {{/|\\\\}}archive-thin.test.tmp{{/|\\\\}}t1.bc" + +CHECK: "inputs": [ +CHECK-NEXT: "{{([a-zA-Z]\:)|/}} +CHECK-SAME: {{/|\\\\}}archive-thin.test.tmp{{/|\\\\}}t2.bc" + +CHECK: "inputs": [ +CHECK-NEXT: "{{([a-zA-Z]:)|/}} +CHECK-SAME: {{/|\\\\}}archive-thin.test.tmp{{/|\\\\}}t3.bc" + +## Ensure backend compilation fails as expected (due to validate.py dummy behavior). +CHECK: error: DTLTO backend compilation: cannot open native object file: + +#--- t1.ll +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @t1() { + ret void +} `````````` </details> https://github.com/llvm/llvm-project/pull/151674 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
